Elevator dispatching system



ELEVATOR DI SPATCHING SYSTEM Filed Aug. 25, 1927 INVENTOR flank E Lewis ATTORNEY Patented Sept. 24, 1935 UNITED STATEfi iPAl'ENT OFFICE ELEVATOR DISPATCHING; SYSTEM Application August 25, 1927, Serial No. 215,392

23 Claims.

My invention relates to dispatching systems for vehicles and it has particular relation to systems for dispatching elevators, hoists and similar devices.

An object of this invention is to provide a dispatching system for a number of vehicles operable over parallel pathways between two fixed terminals, whereby the vehicles will be started in succession from the terminals at regular inter vals of time.

Another object of my invention is to provide a dispatching system, as described in the preceding paragraph, wherein the first vehicle to arrive at a terminal will be the first dispatched from said terminal, regardless of the initial or der of starting of the vehicles.

Another object of my invention is to provide a dispatching system for a bank of elevators, wherein the cars will be started from the terminal floor at successive equal intervals of time and wherein the cars will be dispatched in the order of their arrival at the terminal fioor.

Another object of my invention is to provide a dispatching system for a bank of elevators, wherein if more than one car is at the terminal, the car next scheduled to leave the terminal will be indicated to persons desiring to board the cars.

Another object of my invention is to provide a system of the type described in the preceding paragraph, wherein the door for only that elevator which is scheduled to depart next will be opened, and the doors of any other cars waiting at the terminal will automatically be maintained closed.

Another object of my invention is to provide a dispatching system of the type described, wherein .a signal is given on each of the cars indicating the time of its departure from a terminal floor and wherein, when no cars are at the terminal floor at the scheduled time of departure, the signal will be registered and maintained until one car arrives at the terminal floor, at which time the signal will be transmitted to the arriving car.

My system will be described with reference to the accompanying drawing, wherein,

The sole figure is a diagrammatic view of my dispatching system, as applied to a bank of three elevators.

In dispatching systems of the type used to schedule the operations of a bank of elevators, it is customary to produce a signal indicating to the attendant on each of the cars the time at which his car is scheduled to leave the terminal floor. These systems usually comprise a timing device which produces a signal on each of the several cars at successive equal intervals of time.

The method of operation of these systems is that the cars are initially arranged in a definite order with reference to their times of departure, and the signals produced are transmitted successively to each of the cars, in the predetermined order of departure.

This type of dispatching system is unsatisfactory for the reason that it frequently happens that one car may be required to make a larger number of stops, in making a trip, while a following car makes very few stops, whereby the following car overtakes the first car and arrives at the terminal floor in advance thereof. Thus the dispatching signal intended for the second car is not given until after the dispatching signal is given for the first, thereby causing the second car, already at the terminal floor and ready to depart, to wait an unnecessarily long time before departing, while the first car is required to discharge its passengers and immediately start on its next trip.

My invention overcomes this objectionable feature in that the first car to arrive at the terminal landing is automatically placed in condition to receive the first dispatching signal given thereafter. In this way, any car which, because of traffic conditions, is delayed in its movements toward the terminal, is given the greatest possihis amount of time to discharge passengers and reload before being dispatched for its next trip.

Referring to the drawing, my dispatcher system is illustrated as comprising a constant-speed motor M, preferably of the shunt-wound type, having a variable resistor R. in circuit with its shunt field winding MF and having its armature M suitably coupled, through reduction gearing, to a pair of contact discs l and 2. The contact disc I, hereinafter referred to as the up disc, comprises a 0 contact member 3 arranged on the periphery of the disc and suitably insulated from the driving shaft 6 that connects the disc to the armature M. The particular construction of this contact disc I is not material, since any form of contactor which will produce an impulse of electric current once in each revolution of the driving shaft 4 will be sufficient for the purpose of my invention. The contact disc 2, hereinafter referred to as a down contact disc, comprises a suitable contact memher 5 insulatingly supported by a sleeve 6 mounted upon the shaft 4 and fixed to the shaft 4 by means of a suitable thumb screw l, thus providing for adjustment of the relative angular positions of the contact members 3 and 5. The purpose of this adjustment will be described hereinafter. The contact member 3 cooperates with a suitable stationary contact member 8 for completing a circuit through the contact member each time the shaft 4 makes a complete revolution.

The three elevator cars illustrated in the drawing are designated by the characters A, B and C, respectively. The car A is provided with the usual controlling mechanism (not shown), for moving the car upwardly and downwardly in its shaft and is also provided with a contact device movable in correspondence to the movements of the car. This contact device may be similar to that described in the patent to Smalley, et al., No. 634,220. The contact device illustrated comprises a continuous contact strip It), the length of which is representative of the distance between the upper and lower terminal floors. Adjacent to one end of the contact strip IE! is a short contact strip II, and adjacent to the other end is a short contact strip 12. The relative positioning of the contact strips II and [2 with respect to the contact strip 10 is such that a movable contact bridge I3, operable over the contact strip H) as the car moves from the lower terminal to the upper terminal, will bridge the contact strips I and II when the car is at the first floor and the contact strips l0 and I2 when the car is at the top floor. The contact strip ii is connected in circuit with a relay A-M, while the contact segment I2 is connected in circuit with a relay A-I5.

The elevator car A is provided with a suitable door or gate A-l6, electrically opened through the agency of a bar A-l I, which is operable by a door-opening magnet A-JB to open the door and by a door-closing magnet A--i E3 to close the door. The opening of the door may be controlled in any suitable manner, as by the usual contact members closed by centering the car switch or in any other well-known manner. The opening of the door forms no part of my invention and it has not been deemed necessary to describe such structure in detail.

The door-closing magnet A-lS may be controlled by a suitable door-closing relay A--20, the circuits for which may be controlled either by contact members operated by the car switch or by a suitable counter E. M. F. relay A2l connected across the armature of the hoisting motor. The motor armature is represented by a small circle bearing the legend MA.

The relay A-2I is so proportioned that it is energized by the hoisting motor while the car is operating above a predetermined speed and is deenergized while the car is making a stop. Hence it acts as a safety device which prevents opening of the door while the car is running. This relay is also provided with a pair of normally closed contact members which cooperate with certain other circuits as hereinafter described, to maintain the door closed under certain other conditions.

A suitable dispatching signal A-ZZ is mounted. on the elevator car A, and suitable floor lanterns, such as are usually provided in elevator systems at the upper and lower terminal floors, are designated, respectively, as A-23 and AM.

My system is best described with reference to an assumed operation. Assuming the elevator car A to be above the first floor and travelling downwardly, the approach of the car to the terminal floor will cause the contact brush A-l3 to bridge the contact strips A-ID and A-H to complete a circuit for energizing the relay A--l4,

which circuit extends from line conductor L1, through conductors 3i) and 3|, a single-pole switch 32, conductor 33, contact strip A-iil, contact brush A-I3, contact strip A-l l, conductcr 34, the coil of relay A--l4, conductor 35, normally closed contact members A350, of a relay A.i6, conductor 31, normally closed contact members C351) of a relay C-36, (corresponding to the relay A-it), conductors 38 and 39, nor-- mally closed contact members B-3C*-b of relay B-3t, conductor 49, normally closed contact.

members A361), and conductors M, 42 and 43, to line conductor L2. Relay Ai l thus closes its contact members Al ib, completing a circuit for energizing the relay A36, which circuit extends from line conductor L1, through conductors M and 45, the coil of relay A-36, conductor 41, contact members Al ib, conductor 48, and concluctors 42 and 43 to line conductor L2. The actuation of relay A36 opens contact members A36a and A361), breaking the normal circuit for the relay A-l 4. However, relay Al4 closes its contact members AIM to complete a shunt circuit around the contact members of the relays A3S, E -36 and 0-36, by way of conductors 35 and contact members Aida, and conductors B and 42. Thus, as long as the car remains at the lower terminal floor, the relays A--I4 and A-35 will remain energized.

The relay A-M also completes a circuit for the floor lamp for the first floor, AIM, to indicate that the car A is the first car to start an up trip. This circuit extends from line conductor L1, through conductors El and 52, floor lamp A-24, conductor 53, contact members Ai lc and conductors E54, 42 and 53, to line conductor L2.

Assume that after the arrival of the car A at the first floor, the contact member 3 has been moved by the motor M into engagement with the contact member 3, completing a circuit for the dispatching signal A22 on the elevator car A. This circuit extends from line conductor L2, through conductors 55 and 56 to the motor shaft l, contact member 3, contact member 8, conductors 5?, 58 and 59, contact members AMrZ, conductor 5! dispatching signal A-22, and conductors SI and 5! to line conductor L1.

As the car A approached the first floor, the attendant moved the car switch toward the center to decelerate the car. The deceleration of the car caused the relay A-2l to be deenergized thus opening its contact A-.i!-a and closing its contact members A--2lb. The closing of contact members A2ia opened the safety circuit for maintaining the car door closed while the car was in operation. The closing of the contact members A-2lb prepared the door closing circuits for cooperative action with the dispatching system.

As car A approached still closer to the first floor, the attendant centered his car switch and thereby deenergized the door-closing relay A2Fi to open its contact members and deenergize the door-closing magnet A-iB. The centering of the car switch also energized the door-opening magnet A-I8 which opened the door.

The attendant on car A new moves the car switch A- 5E to start the car on its up trip and to complete a circuit for the door-closing relay A2Ei, which circuit extends from line conductor L1, through conductors 5|, 6! and G3, the car switch A-ES2, contact members 64 and 65 of car switch A-fifl, conductors 6E, 61 and 68, the coil of door-closing relay A-2G, and conductors 69, 42 and 43 to line conductor L2.

The operation of the door-closing relay A-2IJ completes a circuit for the door-closing magnet Al5i, by way of a circuit which extends from line conductor L1, through conductors 5|, .52 and 70, door-closing magnet A-i 9, conductor 7 I, contact members A2ilb, and conductors 13, 42 and 43, to line conductor L2. This action causes the automatic closing of the door A-I6 as the car moves from the first floor. It should be noted here that the door safety relay A2| is not energized to close its door-operating contact members A2lw until after the car accelerates above a predetermined speed.

Assuming the elevator car B to be the next to arrive at the first floor, an operation occurs sim ilar to that described with reference to the elevator car A for operating the floor lamp B24, and the operation of the dispatching signal 13-22 will occur upon the next engagement of contact members 3 and 8, as the motor shaft 4 makes its next complete revolution. Similarly, the elevator car will be dispatched from the first floor upon the third revolution of the motor shaft 4.

The time between the successive operation of the dispatching signals for the cars may be varied by movement of the resistor R, thereby increasing or decreasing the resistance in circuit with the motor field winding ME, thus permitting the time of departure to be varied at will.

As the elevator car A approaches the upper terminal, the contact strips A-l El and A-l 2 will be bridged by the movable contact member A! 3, energizing relays A-it and A-l'5 to cause the operation of the upper terminal floor lantern A-23, and the actuation of the dispatching signal A22, when the contact members 5 and 9 are engaged as the contact disc 2 is rotated by the shaft The operation of these relays and of the contact disc 2 is similar in all respects to the operation of the similar signals at the lower terminal floor and will not be described in detail.

It will be noted that the dispatching signal A-22 cannot be energized unless either relay A- l4 or relay A-!5 is in circuit-closing position. In this manner, only the dispatching signal for that car which is at the terminal may be operated.

Assume that, prior to the departure of elevator car A from the first floor, the elevator car B arrives at that floor. The movable contact member Bi3 associated with the car B will bridge contact strips B-IB and 3- to complete a circuit for the relay BM. However, the circuit for relay B-M extends through the normally closed contact members A3611, by way of a circuit which extends from line conductor L1, through conductors 3t and H3, switch l1, conductor 78, contact strips B-iil and 13-, conductor 79, coil of relay B-M, conductor 89, normally closed contact members Bfifia, conductors BI and 37, normally closed contact members 03%, thence, in series relation, through the normally closed contact members 1336b, and A362), and conductors M, 42 and 3, to line conductor L2. Thus, it is apparent that, as long as elevator car A remains at the first floor and has its relay A-36 energized, the relays BM and B36 are inoperative, and the floor lamp 13-24 will not be illuminated.

Since car B is not to be the next car to leave the floor, it is desirable to have the door for car B remain closed until after the car A has left the floor. Upon discharge of the passengers from car B, the attendant may move the car switch B- SZ sufficiently from central position to bridge contact members 83 and 84, completing a circuit to the door-closing relay B2l3 by way of a circuit which is similar to that traced for the relay A2il for car A. The door-closing magnet Al 9 is thus energized through the relay B2fi, and 5 the door is closed. Relay B--2i3 remains energized until the departure of car A and the subsequent *energization of relay B-M by way of a circuit which extends from line conductor L1, through conductors 3E) and it, switch 11, con ductor '58, contact members Bl0 and B-H, conductor 55, normally closed contact members Bide, conductor 86, normally closed contact members B-Z i-b of the counter E. M. F. relay associated with car B, conductor 87, contact meml5 bers B2911, conductors 83 and 89, the coil of relay B2B, and conductors 9t, 9t and 43, to line conductor L2.

As the car A leaves the first floor, and places car B in condition to be the next car to leave the fioor, the deenergization of relay A36 permits the contact members Bil and Bl| to complete a circuit for relay BM- and relay 3-36. The relay B-Hl opens its contact members BMe,

deenergizing the door-closing relay B-%, and

closes its contact members Bite, energizing the floor lamp B-Jti. The dispatching signal is transmitted thereafter to the car B, as previously described.

It will be noted that the circuit for the door closing relay for any or the cars leads through not only the normally closed contact member for the associated relay A-Hl, Bi l, CM or A-i5, Bid, C95, but also leads through contact strip A-i l, Bi E, CH or contact strip i l-42, Blii, C52, respectively, depending upon whether the car is at the lower or upper terminal and thus the doors are maintained closed by the dispatching system only when the car is at a terminal.

Assume, for example, that the contact member 3 is moved into engagement with contact member 8 at a time when no car is standing at the terminal floor, and, therefore, when there is no car to receive the dispatching signal. The signal will be registered by a relay 9M! and maintained until such time as a car arrives at the floor. The registering relay its is provided at the dispatching station or at any other suitable location and has its coil connected in circuit with the contact members 3 and 8 and with contact members of a second relay Nil. The relay it! is energized at all times when no cars are at the terminal fioor by way of a circuit which extends from line conductor L1, through conductors m2 and I93, the coil of relay Hi6, conductors m4 and 31, and thence, in series, through the normally closed contact members 03th, 33th, and A362), to line conductor L2, as previously traced for these contact members.

Relay lei prepares a circuit for the coil of registering relay me, which circuit is completed by the engagement of contact members 8 and 3. This circuit extends from line conductor L1, through conductors it? and M35, the contact members of relay Hi3, conductor the coil of relay I fill, conductors it! and 5'5, contact members 8 and 3, and conductors 55 and as to line con ductor L2. The relay Mid, when energized, completes a self-holding circuit which extends from line conductor L1, through conductors M2 and H95, the contact members of relay is conductor 36, the coil of relay iilil, conductor M7, the con tact members of relay Hit, and conductors H18, 42 and 43 to supply conductor L2. Thus a circuit is maintained between line conductor L1 and the dispatching signal contact members of each of the up dispatching relays A-M, B-M, etc., so that the first car of the bank to arrive at the lower floor and to operate its associated relay will receive instantly the dispatching signal indicating that it is to depart immediately on its next upward trip.

Relays I09 and I I0 operate in a similar manner to perform the same function for the down dispatching signal when there are no cars at the upper terminal floor. Any of the cars A, B or C may be removed from the automatic dispatching system by opening the switch associated with that car, these switches being designated as 32, I1 and Ill, respectively.

While I have illustrated the dispatching system as being automatic, it is obvious that a manual production of the starting or dispatching impulses might be achieved by providing dispatching but tons for the elevator captain or starter, to be operated at will. Such buttons are shown and designated as H2 and H3 for the up and down directions, respectively.

Another feature of my invention resides in the fact that the interval of time elapsing between the giving of the dispatching signal for any car to start its up trip and to start its down trip may be varied within any desired period by suitable adjustment of the contact disc 2 with reference to the contact disc I.

It sometimes becomes necessary for the elevator captain or starter to recall a car to one of the terminal floors for some special service, prior to the time at which the car would naturally arrive at the terminal in response to its usual dispatching signal. I have, therefore, shown a series of push buttons I Hi, I I5 and I Hi, associated with the elevator cars A, B and C, respectively, which may be operated at will, to flash the dispatching signal on the associated elevator car. It will be remembered that the dispatching signal can be operated automatically only when the car is at a terminal floor. Therefore, if the dispatching signal is illuminated when the car is at any other point, the attendant will know that his car is desired at the dispatching point.

The embodiment of my invention described is merely illustrative and is susceptible of many changes and substitutions in the arrangement of the apparatus described. I therefore do not desire to be limited to the details shown, except as defined in the appended claims.

I claim as my invention:

1. In an elevator system comprising a plurality of cars operable from a terminal in the order of their arrival, a door for each of said cars, means individual to each car for opening its associated door, means individual to each car for closing its associated door, and means responsive to the arrival of any of said cars at a certain terminal and to the closing of its door while at said terminal for thereafter maintaining its door closed until the departure from said terminal of all prior cars.

2. In an elevator system. comprising a plurality of cars operable from the terminal, a. door for each of said cars, means individual to each car for opening its associated door, means individual to each car for closing its associated door, and means responsive to the arrival of a car at the terminal and to the arrival of a later car at the terminal and to operation of the door closing means of said later car for maintaining its door closed until the departure from said terminal of said first arriving car.

3. In an elevator system including a plurality of cars operable from a terminal, a door for each of said cars, a door closing means for each of said cars, and means responsive to the presence of more than one of said cars at said terminal and to the operation of the door closing means of all the cars except the first car to arrive at said terminal for maintaining the door closing means active for all of said cars except said first car to arrive.

4. In an elevator system comprising a pinrality of cars operable from the terminal, a door for each of said cars, means individual to each car for opening its associated door, means individual to each car for closing its associated door, and means responsive to the presence of an early arrived car at the terminal and to the arrival of a later car at the terminal and to the operation of the door closing means of said later car after its arrival at the terminal for maintaining its associated door closed until after the departure of said early car.

5. In an elevator system including a plurality of elevators operable from a terminal, means for giving dispatching signals to said elevators at successive intervals of time in the order in which said cars arrive at said terminal, a floor signal at said terminal for each of said elevators, means for actuating said floor signals one at a time in the order in which said elevators are to receive said dispatching signals, a door for each of said elevators, a door closing means for each door and means responsive to operation of the door closing means and the signal actuating means for preventing the opening of said doors while the cars are at the erminal except one at a time in the order in which said elevators are to receive the dispatching signals.

6. In a dispatching system for a bank of ele vator cars serving a terminal, a. continuously operating means giving a dispatching signal at successive intervals of time regardless of the pres ence of cars at the terminal, means for each of said cars for receiving said signal when at the terminal, means operably responsive to the arrival of the cars at the terminal for causing the cars to receive the dispatching signals in the order in which said cars arrive at the terminal,

and means common to all the cars for causing the first car to arrive after the giving of a signal impulse when no cars are at the terminal to receive its dispatching signal immediately.

7. In a dispatching system for a bank of elevator cars serving a terminal, a starting signal device for each of said cars, a continuously operating means for preparing said signal devices for operation at successive intervals of time regardless of the presence of cars at the terminal, means dependent upon the order of arrival of the cars at a predetermined point for completing the operation of said signal devices in the order in which said cars arrive at the terminal, even though said cars arrive at said terminal in an order different from that in which they previously arrived at said terminal, and means common to all the cars for causing the first car to arrive after the giving of a signal impulse when no cars are at the terminal to receive its dispatching signal immediately.

8. In a dispatching system for a bank of elevator cars serving a terminal, a continuously operating means giving a dispatching impulse at successive intervals of time regardless of the pres- 7 5 ence of cars at the terminal, a starting signal device for each of said cars, means dependent upon the order of arrival of the cars at a predetermined point for causing the dispatching impulses to operate the signal devices in the order in which said cars arrive at the terminal, and means responsive to absence of the cars from the terminal for storing a dispatching impulse given during such absence until the arrival of a car at the terminal.

9. In a dispatching system for a bank of elevator cars serving a terminal, a continuously operating means giving a dispatching impulse at successive intervals of time regardless of the presence of cars at the terminal, a starting signal device for each of said cars, means dependent upon the order of arrival or" the cars at a predetermined point for causing the dispatching impulses to operate the signal devices in the order in which said cars arrive at the terminal, and means responsive to absence of the cars from the terminal for immediately storing the first dispatching impulse given during such absence until the arrival of a car at the terminal.

10. In a dispatching system for a bank of elevator cars serving a terminal, a continuously operating means giving a dispatching impulse at successive intervals of time regardless of the presence of cars at the terminal, a starting signal device for each of said cars, means dependent upon the order of arrival of the cars at a predetermined point for causing the dispatching impulses to operate the signal devices in the order in which said cars arrive at the terminal, means responsive to absence of the cars from the terminal for immediately storing the first dispatching impulse given during such absence, and means responsive to the arrival of the first car after the storing of an impulse for releasing said impulse and restoring the storing means to normal condition.

11. In a dispatcher for elevators where cars are dispatched from two landings, a start signal in each car, two signal giving switches operable at regular intervals, means responsive to an operation of one of said switches for operating said start signal for any one of the cars at only one of said landings and additional means responsive to the operation of the other of said switches for op crating the same signal when the car is at the other of said landings, and means for causing the operation of one switch to be at a predetermined portion of the interval after the operation of the other switch.

12. In a dispatching system for a bank of elevator cars serving a plurality of starting floors, a start signal device in each car, means responsive to the first car to arrive at any one of the starting floors for preparing the start signal device of that car for operation at that floor and for preventing operation of the start signal device of any other car at that iioor while said first car is at that floor, and a single motor giving a dispatching impulse at successive intervals of time for the start signal devices of the cars at each of the starting floors.

13. In a dispatching system for a bank of elevator cars serving an upper terminal and a lower terminal, a single start signal device in each car, means responsive to the first car to arrive at the upper terminal for preparing the start signal device of that car to receive a dispatching impulse while that car is at the upper terminal and for preventing the receipt of a dispatching impulse by the start signal device of any following car at the upper terminal while said first car is at said upper terminal, means responsive to the first car to arrive at the lower terminal for preparing the start signal device of that car to receive a dispatching impulse while that car is at the lower terminal and for preventing the receipt of a dispatching impulse by the start signal device of any following car at the lower terminal while said first car is at said lower terminal, and a continuously operating means giving a dispatching impulse at successive intervals or" time for the start signal devices of the cars at the upper terminal and at the lower terminal.

In a dispatching system for a bank of elevator cars serving an upper terminal and a lower terminal, a single start signal device in each car, a next-car-to-leave signal device for each car at each terminal, a next operating device for each next-car-to-leave signal device, means responsive to the first car to arrive at a terminal for causing its next operating device to operate its next car-todeave signal device at that terminal, a pair of switches, a single motor continuously operating said switches at successive intervals of time, and means responsive to the operation of said switches and said next operating devices for operating the start signal devices for giving dispatching signals to the cars for which the next car-to-leave signal devices are in operation.

15. In an elevator system including a plurality of cars operable from a terminal, a continuously operating means giving a dispatching signal at successive intervals of time regardless of the presence of cars at the terminal, means for each of said cars for receiving said signal when at the terminal, signal selecting means operably responsive to the arrival of the cars at the terminal for causing the cars to receive the dispatching signals in the order in which the cars arrive at the terminal, a door for each of said cars, a door closing means for each of the doors, and means responsive to operation of the door closing means and to the signal selecting means for preventing reopening of said doors while the cars are at the terminal except one at a time in the order in which the cars are to receive the dispatching sig nals.

16. In a dispatching system for a bank of elevator cars serving a terminal, a means for giving a dispatching signal at successive intervals of time regardless of the presence of cars at the terminal, a starting signal device for each of said cars, means dependent upon the order of arrival of the cars at a predetermined point for causing the dispatching signal to operate the signal devices in the order in which said cars arrive at the terminal, a relay, means responsive to absence of the cars from the terminal for operating the relay, and means responsive to operation or" the relay and to operation of the dispatch signal giving means for storing the first dispatching signal during the absence of the cars, and means responsive to the arrival or the first car after the storing of the signal for releasing said signal to operate the signal device of that car.

17. In a dispatching system for a bank of elevator cars serving a terminal, a means for giving a dispatching signal at successive intervals of time regardless of the presence of cars at the terminal, a starting signal device for each of said cars, means dependent upon the order of arrival of the cars at a predetermined point for causing the dispatching signal to operate the signal devices in the order in which said cars arrive at the terminal, a relay, means responsive to absence of the cars from the terminal for operating the relay, means responsive to operation of the relay and to operation of the dispatching signal giving means for storing the first dispatching signal given during the absence of the cars, and means responsive to the arrival of the first car after the storing of the signal for releasing said signal to operate the signal device of that car and restoring the storing means to normal condition.

18. In a dispatching system for a bank of elevator cars serving a terminal, a means for giving a dispatching signal at successive intervals of time regardless of the presence of cars at the terminal, a starting signal device for each of said cars, means dependent upon the order of arrival of the cars at a predetermined point for causing the dispatching signal to operate the signal devices in the order in which said cars arrive at the terminal, a storing relay and an auxiliary relay, means responsive to absence of the cars from the terminal for operating the auxiliary relay, means responsive to operation of the auxiliary relay and to operation of the dispatch signal giving means for operating the storing relay, and means responsive to operation of the storing relay and to the arrival of the first car at the terminal after the absence of the cars from the terminal for operating the signal device of said first car.

19. In a dispatching system for a bank of elevator cars serving a terminal, a means for giving a dispatching signal at successive intervals of time regardless of the presence of cars at the terminal, a starting signal device for each of said cars, means dependent upon the order of arrival of the cars at a predetermined point for causing the dispatching signals to operate the signal devices in the order in which said cars arrive at the terminal, a storing relay and an auxiliary relay, means responsive to absence or" the cars from the terminal for operating the auxiliary relay, means responsive to operation of the auxiliary relay and to operation of the dispatch signal giving means for operating the storing relay, means responsive to operation of the storing relay and to the arrival of the first car at the terminal after the absence of the cars from the terminal for operating the signal device of said first car, and means responsive to the position of the 'car at said predetermined point for restoring the relays to their unoperated condition.

20. In a dispatching system for a bank of elevator cars serving a terminal, a continuously operating means for giving a dispatching signal at successive intervals of time regardless of the presence of cars at the terminal, a starting signal device for each of said cars, means dependent upon the order of arrival of the cars at a predetermined point for causing the dispatching signal to operate the signal devices in the order in which said cars arrive at the terminal, a relay, means responsive to absence of the cars from the terminal for operating the relay, means responsive to operation of the relay and to operation of the dispatch signal giving means for storing the first dispatching signal given during the absence of the cars, and means responsive to the arrival of the first car after the storing of the signal for releasing said signal to operate the signal device of that car.

21. In a dispatching system for a bank of elevator cars serving a terminal, a continuously operating means for giving a dispatching signal at successive intervals of time regardless of the presence of cars at the terminal, a starting signal device for each of said cars, means dependent upon the order of arrival of the cars at a predetermined point for causing the dispatching signal to operate the signal devices in the order in which said cars arrive at the terminal, a relay, means responsive to absence of the cars from the terminal for operating the relay, means responsive to operation of the relay and to operation of the dispatch signal giving means for storing the first dispatching signal given during the absence of the cars, and means responsive to the arrival of the first car after the storing of the signal for releasing said signal to operate the signal device of that car and restoring the storing means to normal condition.

22. In a dispatching system for a bank of elevator cars serving a terminal, a continuously operating means for giving a dispatching signal at successive intervals of time regardless of the presence of cars at the terminal, a starting signal device for each of said cars, means dependent upon the order of arrival of the cars at a predetermined point for causing the dispatching signals to operate the signal devices in the order in which said cars arrive at the terminal, a storing relay and an auxiliary relay, means responsive to ab sence of the cars from the terminal for operating the auxiliary relay, means responsive to operation of the auxiliary relay and to operation of the ispatch signal giving means for operating the storing relay, and means responsive to operation of the storing relay and to the arrival of the first car at the terminal after the absence of the cars from the terminal for operating the signal device of said first car.

23. In a dispatching system for a bank of elevator cars serving a terminal, a continuously operating means for giving a dispatching signal at successive intervals of time regardless of the presence of cars at the terminal, a starting signal device for each of said cars, means dependent upon the order of arrival of the cars at a predetermined point for causing the dispatching signals to operate the signal devices in the order in which said cars arrive at the terminal, a storing relay and an auxiliary relay, means responsive to absence of the cars from the terminal for operating the auxiliary relay, means responsive to operation of the auxiliary relay and to operation of the dispatch signal giving means for operating the storing relay, means responsive to operation of the storing relay and to the arrival of the first car at the terminal after the absence of the cars from the terminal for operating the signal device of said first car, and means responsive to the position of the car at said predetermined point for restoring the relays to their unoperated condition.

FRANK E. LEWIS. 

